Broad objectives: To perfect a software-based switch access device for the service of profoundly disabled or paralyzed individuals. The switch, currently named the Muscle Communicator, will provide access to computerized devices that allow text entry, speech generation, Internet access, and environmental or hardware control. The means of input, currently limited to EMG, will be broadened to include methods such as EOG, EEG, or pressure. This will make high-accuracy device access available to people with a greater range of disabilities than is currently possible. Specific technical aims for this phase: [A] To integrate into the current software an auto-calibration routine that will reduce the need for time-consuming manual adjustments. [B] To implement software routines that distinguish intentional activity from unintentional. [C] To integrate a failsafe hardware alarm into the circuit as a call bell or emergency alarm. [D] To assess these improvements in clinical trials with three able-bodied and three severely disabled volunteers. Benefits: The success of this project will result in a high-accuracy switch access device that is usable by individuals with physical disabilities of all mobility levels. In the United States, there are 30,000 people with ALS (Lou Gehrig's disease) and 50,000 with high-level brain stem stroke, two conditions that can cause severe paralysis. Individuals with high mobility can use pressure switches. Those with medium or low levels can use EMG or EOG, and those with little of no motion can use EEG or LFP (local field potentials). The automatically adjusting sensitivity of the software will adapt to declining and recovering levels of physical ability. This will obviate the need to buy many types of access devices for different stages of a condition